You don't need a car in Hong Kong - you can literally get anywhere via some form of public transit.

In Tokyo or Osaka, same thing.

Ok I get what you are saying. Hong Kong definitely has good transit. Tokyo as well, but it technically falls into the category of east asia. Generally the highly developed countries/city states in Asia do have terrific, and clean public transportation.

Southeast Asia is comprised of Hong Kong, Singapore, Thailand, Cambodia, Vietnam, Laos, Philippines, etc. Most of which have absolutely horrific public transportation.

I think I would put places like London and Paris in the same ballpark as the highly developed Asian locales. There is seemingly a metro station on every corner in Paris.